Scala achieve WordCount simple case

Scala achieve WordCount simple case

下面的代码是在IDEA中进行单词计数的小案例

object WordCount {
  def main(args: Array[String]): Unit = {
  //定义一个List
    val list = List("java scala java","scala python scala")
  //处理原始数据,获取每个word  
    val words = list.flatMap(_.split(" "))
    println(words)//List(java, scala, java, scala, python, scala)
  //改变格式，为元组（word，1）  
    val wordOne = words.map((_,1))
    println(wordOne)//List((java,1), (scala,1), (java,1), (scala,1), (python,1), (scala,1))
  //根据（word，1）中的key值 word 进行分组  
    val wordG = wordOne.groupBy(_._1)
    println(wordG)//Map(scala -> List((scala,1), (scala,1), (scala,1)), java -> List((java,1), (java,1)), python -> List((python,1)))
    //获取map中的value，对value中的tuple的._2(也就是1)进行统计（也就是叠加）
    
    val wordCount = wordG.mapValues(_.foldLeft(0)(_+_._2))
    println(wordCount)//Map(scala -> 3, java -> 2, python -> 1)

    /**/
  }
}